The present invention relates to the field of backup power sources, and more particularly to backup power sources for computer hardware.
The size and complexity of computing networks and data centers has rapidly grown, and the number of servers and other devices within these data centers has expanded greatly. Business requirements changed introducing multiple operating systems, optimized hardware configurations, more rapid application development cycles, and requirements for high reliability and availability. The cost, size, energy consumption, and complexity of data centers built around individual servers, personal computers (PCs), storage devices, etc., became prohibitive to maintain. Data centers have evolved away from individual servers and PCs to rack-mounted “blade” server “farms” and computing clusters. To increase the speed of execution of software programs, improve security, and search databases of increasing size and complexity, software programs often execute different tasks (e.g., modules, functions, transactions, etc.) on servers and other computing hardware optimized for that type of transaction. Examples of servers optimized for specific tasks are: database servers, file servers, mail servers, print servers, web servers, rendering (e.g., graphics) servers, and application servers.
Data centers utilize various strategies to obtain goals, which include high reliability, high availability, preventing data loss or corruption, and avoiding negative customer experiences. One strategy is utilizing uninterruptable power supplies (UPS) to support the operations of the data center (e.g., servers). When power failures occur, UPSs can support the data center from minutes to hours until backup power is activated (e.g., emergency generators), or the primary power supply (e.g., grid power) is restored. A second strategy is to monitor available backup power and to “gracefully” shut down servers and other aspects of the data center in a controlled fashion to minimize customer impacts and prevent data loss or corruption. A graceful shutdown may include preventing additional tasks or requests from initiating, completing transactions in progress, saving data, suspending network activity, pausing the server, and powering off a server.